1. Field Of The Invention
The present invention relates generally to the field of securement structures for aligning terminal blocks, input/output devices and other electrical components within enclosures and the like. More particularly, the invention relates to a self-locking, clip-in structure that can easily and quickly be mounted and removed straight on and off of a standard support rail, and that can be adapted for use as a terminal block or other device support.
2. Description Of The Related Art
A number of systems have been developed and are currently in use for mounting small components, particularly electrical components, in enclosures. Such systems include various conduit and rail structures useful for channeling wires to and from the components in a neat and orderly manner, facilitating installation and servicing. One popular system of this type is based upon a standard set of flanged rails that can be cut to a desired length and attached via screws to the interior of an enclosure. The rails, commonly referred to as xe2x80x9cDINxe2x80x9d rails, have either inwardly or outwardly projecting raised flanges along their length for receiving the components. The components, including a wide array of modular elements such as terminal blocks, input/output modules, dip switches, small motor drives, contactors, circuit breakers, overload relays, communication/control modules, and so forth, feature corresponding structures designed to interface with the rail flanges to hold the components securely in place during installation and use.
Known component mounting structures include screw-down and screwless styles. Screw-down structures generally clip into place along the DIN rail and may be slid along the rail for positioning. A screw held over one of the rail flanges is then driven into the flange to anchor the component in place. In addition to the cost of the screw and associated holding elements, a disadvantage of these structures is the need to independently secure each component via the screw. This process is not only time consuming, but may result in misalignment on the rail due to twisting of the component under the influence of the screw-down torque. In many applications, therefore, the screwless mounting arrangements are often preferable.
The DIN rail attachment mechanism most commonly used is one with a fixed catch on one side and a moveable catch or snap on the opposite side. These arrangements typically include a component module having a hook-shaped rigid foot that is slipped over a first of the rail flanges, and a deformable leg that is then snapped over the opposite flange to secure the component to the rail. Because the modules are typically made of a moldable plastic material due to its good electrical insulation capabilities, metallic clips and the like are often provided in the rail interface features to bind the component more securely in place on the rail. For removal, the deformable leg may be bent free of the rail flange and the component may be removed by unhooking the rigid foot from the opposite flange. For these approaches, since one catch is fixed, DIN rail removal requires that the device must translate about 0.03-0.05 inches relative to the DIN rail after prying the opposite side. In many cases, a combined translation and rotational motion of the device relative to the DIN rail is required for removal.
In recent years a new generation of modular control and communication products has evolved for motor starter and other applications. These products being modular in nature, must make electrical connections to each other and may be DIN rail mounted within an enclosure. The electrical connections between modules could be achieved with separate plug-in connectors, but this approach would be very inefficient and costly. An effective method utilized to make these connections is to first design the modular housings such that they slide into each other from the top via a dovetail slot arrangement. Electrical connections are then made with mating contacts between the opposite housings that slide into contact as the two housings slide together.
The sliding dovetail arrangement produces an effective method for mechanical and electrical connections between modular housings but presents a major challenge for DIN rail mounting. Because with this approach the housings must slide off the DIN rail vertically with no lateral translation or rotation, traditional DIN rail release mechanisms will not work. Therefore, for the sliding dovetail approach to be effective, both catches or snaps must be released simultaneously. This then allows the module to be pulled straight off the DIN rail while sliding along adjacent modules on either side. An additional requirement of communication/control modules is that an electrical connection be made to the DIN rail for grounding and EMI noise issues.
While existing screwless DIN rail mounting structures provide an attractive solution to the problem of quickly and easily attaching components in desired rail locations, they are not without drawbacks. As noted above, existing mechanisms require considerable translational and/or rotational movement of the device to remove it from the DIN rail, and often lack a sufficient securement force to prevent lateral motion of the device. The requisite rotational movement may be disadvantageous in many applications. Furthermore, existing devices are often difficult to remove from the DIN rail due to this requisite rotational movement and the considerably high spring force in the deformable leg. For example, removal may be complicated where there is limited space, or where the point of access is limited. Due to the rotational movement, existing mechanisms also preclude the possibility of the sliding dovetail approach, discussed above, for attaching adjacent DIN rail devices. Existing DIN rail mounting structures also lack grounding mechanisms for electrical coupling to the DIN rail. As discussed above, existing structures are generally made of plastic, while only a limited amount of metal may be used in the hook shaped foot to enhance the securement force.
There is a need, therefore, for an improved arrangement for mounting components along DIN rails. The arrangement should be of a straightforward design that can be easily manufactured and assembled on the rail. In particular, there is a need for a DIN rail mounting structure that provides a straight attachment and removal mechanism. In accordance with this straight on/off mechanism, there is a further need for a grounding mechanism to complete an electrical connection to the DIN rail, an electrical-mechanical coupling mechanism for an adjacent module, and a superior holding force to prevent lateral movement while minimizing the number of different parts in the overall product.
The present technique features a detachable securement apparatus configured for a mounting rail, wherein the mounting rail has a first and second mounting flange extending lengthwise along opposite sides of a support section. The apparatus has a body, a securement assembly and a release assembly. Extending from the body, the securement assembly has first and second interface members, each including a contact region configured to exert a holding force on the first and second mounting flanges, respectively. The release assembly is configured for removing the holding force on both the first and second mounting flanges to allow vertical removal of the body. The release assembly has an engagement member coupled to the body and to the first and second interface members, and is engagable on a side of the body.
The technique also features a module mounting system for removably mounting to a mounting rail, wherein the rail has first and second mounting flanges extending lengthwise along opposite sides of a support section. The system includes a securement assembly and a vertical release assembly. The securement assembly has first and second spring-forced feet configured to exert a holding force on the first and second mounting flanges, respectively. The vertical release assembly includes a lateral actuator configured for simultaneously releasing the spring-forced feet from the mounting rail to allow vertical removal of the body.
A method is also contemplated for attachment and detachment with a rail mount assembly. The method includes springably coupling first and second sides of a conductive mounting member to the first and second flange of a mounting rail, respectively. The method also includes laterally engaging a release actuator coupled to the mounting member. The method also includes simultaneously releasing the first and second sides of the mounting member from the first and second flange, respectively.